Update: As has been pointed out, this doesn’t supplement the existing battery, it replaces it in the phone. So you get a longer battery life, but not more than double. You could of course take the spare battery as a backup and switch it out when necessary. Still worth the $50 investment if you’re a heavy user. Apologies for any confusion.

The Galaxy Nexus ships with a 1750mAh rechargeable battery, which when coupled with the 4.65-inch display and 1.2GHz dual-core processor, probably isn’t going to make it through the day. That is, if you intend on actually using it for calls, apps, and surfing the web on a regular basis.

Samsung has clearly realized this and decided to turn it into a marketing opportunity. How would you like to more than double the battery life of your Galaxy Nexus? Well, if you hand over $49.99 to Samsung, they’ll gladly ship you the i515 Battery Bundle Kit.

The kit includes an extended battery and battery cover, meaning your Galaxy Nexus is going to get a bit thicker and heavier, but in return it will definitely last the day and then some. That’s because the 1750mAh standard battery is supplemented with a 2100mAh second battery hidden behind the new cover.

Why didn’t Samsung just ship a bigger battery with the Galaxy Nexus in the first place? They’d probably blame us, the consumers for that. We all want super-thin phones with big screens, making it tough to include a large battery in the design. But at least Samsung has taken the initiative and brought out the kit right at the start of the smartphone’s life. You really can’t argue with the price, either.

Although it may be seen as cheating, with the addition of the extended battery does the Galaxy Nexus officially become the longest-lasting smartphone between charges? Or does another extended battery solution offering even more juice for a current Android or iPhone beat it?